1.Effects of Yangxin Tongmai Formula (养心通脉方) on Methylation Key Genes and the PERK/ATF4/CHOP Signaling Pathway in Myocardial Tissue of Coronary Heart Disease Model Rats with Blood Stasis Syndrome
Chun ZHANG ; Shumeng ZHANG ; Yan MAO ; Xing CHEN ; Huifang KUANG ; Yi YANG ; Lingli CHEN ; Jie LI
Journal of Traditional Chinese Medicine 2026;67(7):784-791
ObjectiveTo investigate the mechanism of Yangxin Tongmai Formula (养心通脉方, YTF) in trea-ting coronary heart disease with blood stasis syndrome based on DNA methylation. MethodsSeventy-two SD rats were randomly divided into a control group (n=12) and a modeling group (n=60). The modeling group was subjected to a high-fat diet, intragastric administration of vitamin D3, and subcutaneous injection of isoprenaline to establish the rat model of coronary heart disease with blood stasis syndrome. Forty-one successfully modeled rats were then randomly allocated into model group, YTF low-, medium-, and high-dose groups, and the atorvastatin calcium group, with 8 rats in each group and 1 rat reserved. The YTF low-, medium-, and high-dose groups received YTF at 6, 12, and 18 g/(kg·d) by gavage, respectively. The atorvastatin calcium group received atorvastatin calcium tablets at 1.8 mg/(kg·d) by gavage. The control group and the model group received 0.9% sodium chloride injection at 4 ml/(kg·d) by gavage. All administrations were performed once daily for 3 weeks. Twenty-four hours after the last administration, serum lipid levels including total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), myocardial enzymes including cardiac troponin T (cTnT), creatine kinase MB (CK-MB), and lactate dehydrogenase (LDH), and inflammatory factors including interleukin-1β (IL-1β) and interleukin-10 (IL-10) were detected by ELISA. Pathological changes in myocardial tissue were observed via HE staining. Whole blood DNA methylation sequencing was used to analyze differential methylation gene expression among the control group, model group, and YTF high-dose group. Western Blotting was used to verify the protein levels of the key genes and downstream signaling pathways. ResultsCompared to the control group, the model group showed increased levels of TC, TG, LDL-C, cTnT, CK-MB, LDH, and IL-1β, along with decreased levels of HDL-C and IL-10 (P<0.05 or P<0.01). Compared to the model group, all treatment groups exhibited decreased levels of TC, LDL-C, CK-MB, and LDH, along with increased IL-10 levels. Among these, the high-dose YTF group demonstrated superior efficacy in reducing cTnT levels compared to the other TCM groups (P<0.05 or P<0.01). HE staining indicated that the YTF high-dose group ameliorated myocardial cell swelling, disordered arrangement, pyknosis, and disappearance of nuclei, thereby reducing myocardial cell damage. Whole blood DNA methylation sequencing identified 240 differentially methylated genes shared by the control group, model group, and YTF high-dose group, including 109 hypermethylated and 131 hypomethylated genes; eif2ak3 was identified as a key differentially methylated gene. Compared to the control group, the model group exhibited increased protein levels of eukaryotic translation initiation factor 2 alpha kinase 3 (eIf2ak3), phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (p-PERK), activating transcription factor 4 (ATF4), C/EBP homologous protein (CHOP), and Bax, along with a decreased level of B-cell lymphoma-2 (Bcl-2) protein (P<0.05 or P<0.01). Compared to the model group, the YTF high-dose group showed decreased protein levels of eIf2ak3, p-PERK, ATF4, CHOP, and Bax, and an increased level of Bcl-2 protein (P<0.05 or P<0.01). ConclusionYTF may regulate key differentially methylated genes such as eIf2ak3 and the PERK/ATF4/CHOP signaling pathway, thereby inhibiting endoplasmic reticulum stress, reducing myocardial cell apoptosis, and exerting therapeutic effects in coronary heart disease blood stasis syndrome.
2.Comparison of Wild and Cultivated Gardeniae Fructus Based on Traditional Quality Evaluation
Yuanjun SHANG ; Bo GENG ; Xin CHEN ; Qi WANG ; Guohua ZHENG ; Chun LI ; Zhilai ZHAN ; Junjie HU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):225-234
ObjectiveBased on traditional quality evaluation of Gardeniae Fructus(GF) recorded in historical materia medica, this study systematically compared the quality differences between wild and cultivated GF from morphological characteristics, microscopic features, and contents of primary and secondary metabolites. MethodsVernier calipers and analytical balances were used to measure the length, diameter and individual fruit weight of wild and cultivated GF, and the aspect ratio was calculated. A colorimeter was used to determine the chromaticity value of wild and cultivated GF, and the paraffin sections of them were prepared by safranin-fast green staining and examined under an optical microscope to observe their microstructure. Subsequently, the contents of water-soluble and alcohol-soluble extracts of wild and cultivated GF were detected by hot immersion method under the general rule 2201 in volume Ⅳ of the 2020 edition of the Pharmacopoeia of the People's Republic of China, the starch content was measured by anthrone colorimetric method, the content of total polysaccharides was determined by phenol-sulfuric acid colorimetric method, the sucrose content was determined by high performance liquid chromatography coupled with evaporative light scattering detection(HPLC-ELSD), and the contents of representative components in them were measured by ultra-performance liquid chromatography(UPLC). Finally, correlation analysis was conducted between quality traits and phenotypic traits, combined with multivariate statistical analysis methods such as principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA), key differential components between wild and cultivated GF were screened. ResultsIn terms of traits, the wild GF fruits were smaller, exhibiting reddish yellow or brownish red hues with significant variation between batches. While the cultivated GF fruits are larger, displaying deeper orange-red or brownish red. The diameter and individual fruit weight of cultivated GF were significantly greater than those of wild GF, while the blue-yellow value(b*) of wild GF was significantly higher than that of cultivated GF. In the microstructure, the mesocarp of wild GF contained numerous scattered calcium oxalate cluster crystals, while the endocarp contained stone cell class round, polygonal or tangential prolongation, undeveloped seeds were visible within the fruit. In contrast, the mesocarp of cultivated GF contained few calcium oxalate cluster crystals, or some batches exhibited extremely numerous cluster crystals. The stone cells in the endocarp were predominantly round-like, with the innermost layer arranged in a grid pattern. Seeds were basically mature, and only a few immature seeds existed in some batches. Regarding primary metabolite content, wild GF exhibited significantly higher total polysaccharide level than cultivated GF(P<0.01). In category-specific component content, wild GF exhibited significantly higher levels of total flavonoids and total polyphenols compared to cultivated GF(P<0.01). Analysis of 12 secondary metabolites revealed that wild GF exhibited significantly higher levels of Shanzhiside, deacetyl asperulosidic acid methyl ester, gardenoside and chlorogenic acid compared to cultivated GF(P<0.01). Conversely, the contents of genipin 1-gentiobioside, geniposide and genipin were significantly lower in wild GF(P<0.01). ConclusionThere are significant differences between wild and cultivated GF in terms of traits, microstructure, and contents of primary and secondary metabolites. At present, the quality evaluation system of cultivated GF remains incomplete, and this study provides a reference for guiding the production of high-quality GF medicinal materials.
3.Development and validation of the rapid health aging assessment scale for the Chinese population
Bingqi YE ; Jialu YANG ; Jianhua LI ; Wunong CHEN ; Jianhua YE ; Xiaotao ZHOU ; Yong WANG ; Siqi LI ; Qi ZHANG ; Wanying ZHAO ; Jiayi SONG ; Chun WANG ; Yan LIU ; Min XIA
Chinese Journal of Preventive Medicine 2025;59(7):1078-1083
Objective:To develop a rapid assessment scale for healthy aging suitable for the Chinese population.Methods:Based on existing healthy aging assessment scales, national standards, and expert consensus, an initial Healthy Aging Rapid Assessment Scale was drafted through two rounds of expert consultation. A pre-survey was conducted with 3 220 subjects recruited from Guangzhou between July 2023 and July 2024. Items were screened through item analysis and exploratory factor analysis to form the final scale. Reliability and validity of the final scale were validated across five cities: Guangzhou, Dongguan, Shenzhen, Baoding, and Chuxiong.Results:The initial version comprised 36 items, while the finalized scale contained 18 items across three dimensions: metabolic health, mental health, and cognitive health. Test-retest reliability ranged from 0.71 to 0.81 across all study sites. The Spearman-Brown coefficient varied between 0.91-0.96, Cronbach′s α between 0.77-0.83, comparative fit index (CFI) between 0.90-0.98, goodness-of-fit index (GFI) between 0.90-0.99, and root-mean-square error of approximation (RMSEA) between 0.03-0.09. For the three dimensions, reliability and validity metrics demonstrated consistency: Spearman-Brown coefficients 0.87-0.99, Cronbach′s α 0.77-0.83, CFI 0.90-0.98, GFI 0.90-0.99, and RMSEA 0.03-0.09 across four regions.Conclusion:The developed Healthy Aging Rapid Assessment Scale for the Chinese population exhibits robust reliability and validity.
4.Distribution characteristics and long-term change trend of body mass index in Chinese older adults aged 65 years and above
Li QI ; Chen CHEN ; Sirui CHEN ; Zhipei LI ; Sixin LIU ; Jinhui ZHOU ; Jiahao CHEN ; Hao QIAN ; Chun TAN ; Xianglong DAI ; Ziyue ZHU ; Jun WANG ; Xi MENG ; Wenhui SHI ; Yuebin LYU ; Xiaoming SHI
Chinese Journal of Preventive Medicine 2025;59(6):908-915
Objective:To describe the body mass index (BMI) level and long-term trends of Chinese older adults aged 65 and above.Methods:Older adults aged 65 and above from six waves (2002-2018) of the China Longitudinal Healthy Longevity Survey were selected as the study population. Multiple cross-sectional design with six survey waves conducted in 2002, 2005, 2008, 2011, 2014, and 2018 was adopted, enrolling 15 647, 15 358, 15 622, 9 166, 6 302, and 12 417 participants, respectively. Additionally, a total of 13, 755 participants were included in the cohort study design. Relevant information was collected through questionnaires and physical examinations. The χ2 trend test was used to compare the changes in the rates of underweight and overweight/obesity over the years, and the linear mixed-e?ects model (LMM) was used to fit trajectory curves of BMI changes with advancing age in older adults. Results:The baseline ages of the participants included in 2002, 2005, 2008, 2011, 2014, and 2018 were (85.16±11.26), (84.23±11.83), (84.99±12.16), (81.10±11.86), (78.89±11.30), and (83.08±12.42) years, respectively, with a relatively high proportion of females and rural residents. In the cohort study, the 13 755 participants had a median ( Q1, Q3) follow-up time of 6.5 (5.2, 10.0) years, with a cumulative follow-up duration of 109 041 person-years. In each wave, males had higher BMI than females, urban residents had higher BMI than rural residents, and BMI gradually decreased with increasing age (all P<0.001). The mean BMI of older adults in China increased from (19.37±3.80) kg/m2 in 2002 to (22.04±4.01) kg/m2 in 2018 ( P<0.001). Across all survey years, the prevalence of underweight was consistently higher in women than in men and in rural areas than in urban areas, with an upward trend as age increased (all P<0.001). In 2018, the underweight rates in the 65-79, 80-89, 90-99, and ≥100-year-old age groups were 8.0%, 16.7%, 26.2%, and 35.5%, respectively. Meanwhile, the prevalence of overweight/obesity was higher in men than in women and in urban areas than in rural areas, showing a declining trend with advancing age (all P<0.001). The prevalence of underweight among the older adults decreased significantly from 45.2% in 2002 to 18.9% in 2018 ( P<0.001), while the prevalence of overweight/obesity increased from 11.0% in 1998 to 29.6% in 2018 ( P<0.001). The trajectory curves fitted by the LMM model showed that individuals born in later decades had higher BMI levels at the same age compared to earlier cohorts. Conclusion:From 2002 to 2018, the BMI level among Chinese older adults showed an increasing trend. The prevalence of underweight showed a declining trend, while the rates of obesity and overweight increased. However, the underweight rate remained notably high among the oldest old.
5.Study on the elements of medical service value from the perspective of cancer patients based on free-form comment text analysis
Xiao CHEN ; Yuhong ZHANG ; Chun YANG ; Pengfei HAN ; Jianyou CHEN ; Yuxia ZHANG
Chinese Journal of Hospital Administration 2025;41(2):139-145
Objective:To explore the focus points and emotional tendencies of cancer patients regarding medical services from their free-form comments, and to analyze the elements of perceived medical service value by patients.Methods:A tertiary general hospital in Shanghai invited patients to evaluate inpatient services through the assessment module of a patient satisfaction management platform, which included open-ended questions in the patient satisfaction survey. This study extracted free-form comment texts from cancer patients regarding medical services collected from September 2022 to August 2023 from this platform, forming a corpus of patient opinions. A hybrid method combining manual coding and natural language processing techniques was used to conduct sentiment analysis and topic modeling on the free-form comment texts. Descriptive analysis was performed on the comment themes and emotions, and logistic regression analysis was used to explore the relationship between patient negative comments and patient satisfaction and loyalty.Results:A total of 10 446 comment texts provided by cancer patients were included. The most frequently targeted objects in the comments were nurses (2 223 cases), followed by doctors (1 125 cases) and nursing assistants (162 cases). The results of sentiment analysis showed that 7 058 patients made positive comments, 1 958 patients made negative comments, 1 114 patients made neutral comments, and 316 patients made mixed comments. The results of topic analysis showed that the five most frequently mentioned themes by cancer patients were humanistic care (1 327 times), information provision, communication, and education (589 times), diet (582 times), effectiveness of diagnosis and treatment (506 times), and medical staff responsibility (489 times). Logistic regression analysis showed that negative evaluations of humanistic care ( OR=0.306, P<0.001), professional technical level ( OR=0.425, P=0.010), information provision, communication, and education ( OR=0.475, P<0.001), and response to needs ( OR=0.412, P=0.026) were significantly associated with decreased patient satisfaction. Negative evaluations of humanistic care ( OR=0.407, P<0.001), professional technical level ( OR=0.466, P=0.009), and information provision, communication, and education ( OR=0.557, P<0.001) were significantly associated with decreased patient loyalty. Conclusions:Hospital managers should value the role of patient free-form comment texts in improving medical services and make full use of natural language processing techniques for information mining. In addition, the results of this study show that patient comments mainly involve the interpersonal and functional aspects of service, especially the interpersonal interactions, which are often the " critical moments" for patients to critically evaluate hospital services during their service experience.
6.A hierarchical deep learning model based on whole slide imaging of cerebrospinal fluid cells for rapid diagnosis of meningeal carcinomatosis
Kun CHEN ; Xiangyu LI ; Qianqian XU ; Zhiyu XU ; Di WANG ; Huanhuan QIN ; Guangjie JIANG ; Haoqin JIANG ; Qiong ZHAN ; Mengxi GE ; Xin LI ; Chun XU ; Ming GUAN
Chinese Journal of Laboratory Medicine 2025;48(12):1558-1564
Objective:To develop a convolutional neural network model of whole slide imaging of cerebrospinal fluid cells for rapid and accurate identification and classification of tumor cells in cerebrospinal fluid.Methods:A total of 8 692 cerebrospinal fluid cytology smears from Huashan Hospital Affiliated to Fudan University from January 2nd, 2019, to December 27th, 2024. As randomly assigned, the training set included 4 941 benign and 1 745 malignant samples, while the validation set comprised of 1 368 benign and 638 malignant samples. Whole-slide digital images were acquired using a cytopathology scanner, cells (clusters) were annotated for classification, and a deep learning model was constructed via tiled image patches for cell detection and classification. Model performance was evaluated using accuracy, sensitivity, specificity, and other indicators. The classification efficiency of manual microscopy was compared.Results:The model achieved a mean precision of 96.75% for cerebrospinal fluid cell classification. For malignant tumor cells, the classification accuracy was 96.61% (mAP=98.36%, AUC=0.97). Subtype classification accuracies for epithelial/epithelioid tumors and small round cell tumors were 97.13% (AUC=0.98) and 95.58% (AUC=0.93), respectively. Compared with manual microscopy, which took (9.70±0.82) minutes for classifying 200 cells, (18.27±1.21) minutes for 500 cells, and often exceeded 60 minutes or infeasible for full slides, the AI model took (3.46±0.49) seconds for 200 cells, (6.76±0.82) seconds for 500 cells, and a median of 48.57 seconds for full slides ( P<0.001), representing an efficiency improvement of approximately 161-170 times, significantly enhancing diagnostic efficiency. Conclusion:This fully automated hierarchical deep learning model enables efficient and accurate tumor cell identification and classification in CSF, providing an effective auxiliary tool for the rapid diagnosis of meningeal carcinomatosis.
7.Thalidomide mitigates Crohn's disease colitis by modulating gut microbiota,metabolites,and regulatory T cell immunity
Chao-Tao TANG ; Yonghui WU ; Qing TAO ; Chun-Yan ZENG ; You-Xiang CHEN
Journal of Pharmaceutical Analysis 2025;15(4):817-834
Thalidomide(THA)is renowned for its potent anti-inflammatory properties.This study aimed to eluci-date its underlying mechanisms in the context of Crohn's disease(CD)development.Mouse colitis models were established by dextran sulfate sodium(DSS)treatment.Fecal microbiota and metabolites were analyzed by metagenomic sequencing and mass spectrometry,respectively.Antibiotic-treated mice served as models for microbiota depletion and transplantation.The expression of forkhead box P3+(FOXP3+)regulatory T cells(Tregs)was measured by flow cytometry and immunohistochemical assay in colitis model and patient cohort.THA inhibited colitis in DSS-treated mice by altering the gut microbiota profile,with an increased abundance of probiotics Bacteroides fragilis,while pathogenic bacteria were depleted.In addition,THA increased beneficial metabolites bile acids and significantly restored gut barrier function.Transcriptomic profiling revealed that THA inhibited interleukin-17(IL-17),IL-1β and cell cycle signaling.Fecal microbiota transplantation from THA-treated mice to microbiota-depleted mice partly recapitulated the effects of THA.Specifically,increased level of gut commensal B.fragilis was observed,correlated with elevated levels of the microbial metabolite 3alpha-hydroxy-7-oxo-5beta-cholanic acid(7-ketolithocholic acid,7-KA)following THA treatment.This microbial metabolite may stable FOXP3 expression by targeting the receptor FMR1 autosomal homolog 1(FXR1)to inhibit auto-phagy.An interaction between FOXP3 and FXR1 was identified,with binding regions localized to the FOXP3 domain(aa238-335)and the FXR1 domain(aa82-222),respectively.Conclusively,THA modu-lates the gut microbiota and metabolite profiles towards a more beneficial composition,enhances gut barrier function,promotes the differentiation of FOXP3+Tregs and curbs pro-inflammatory pathways.
8.Immunomodulatory effect of short-chain fatty acids in hepatic encephalopathy and its potential diagnostic value
Weiyu CHEN ; Dewen MAO ; Han WANG ; Yang DU ; Wenqian FENG ; Lei FU ; Chun YAO
Journal of Clinical Hepatology 2025;42(5):954-962
Hepatic encephalopathy(HE)is a common complication of severe liver disease in the end stage,and it is urgently needed to improve the rate of effective treatment and clarify the pathogenesis of HE.The liver is a crucial hub for immune regulation,and disruption of immune homeostasis is a key factor in the pathological mechanisms of HE.As the main metabolites of intestinal flora,short-chain fatty acids(SCFAs)play a vital role in the biological processes of both innate and adaptive immunity and can regulate the proliferation and differentiation of immune cells maintain the homeostasis of intestinal microenvironment and the integrity of barrier function.Studies have shown that SCFAs participate in bidirectional and dynamic interactions with the liver-gut-brain axis through immunomodulatory pathways,thereby playing an important role in the diagnosis,treatment,and prognostic evaluation of HE.Starting from the immunoregulatory effect of SCFAs,this article summarizes and analyzes the crosstalk relationship between SCFAs and the liver-gut-brain axis and the significance of SCFAs in the diagnosis and treatment of HE,in order to provide new ideas for optimizing clinical prevention and treatment strategies.
9.The Adoption of Non-invasive Photobiomodulation in The Treatment of Epilepsy
Ao-Yun LI ; Zhan-Chuang LU ; Li CAO ; Si CHEN ; Hui JIANG ; Chang-Chun CHEN ; Lei CHEN
Progress in Biochemistry and Biophysics 2025;52(4):882-898
Epilepsy is a chronic neurological disease caused by abnormal synchronous discharge of the brain, which is characterized by recurrent and transient neurological abnormalities, mainly manifested as loss of consciousness and limb convulsions, and can occur in people of all ages. At present, anti-epileptic drugs (AEDs) are still the main means of treatment, but their efficacy is limited by the problem of drug resistance, and long-term use can cause serious side effects, such as cognitive dysfunction and vital organ damage. Although surgical resection of epileptic lesions has achieved certain results in some patients, the high cost and potential risk of neurological damage limit its scope of application. Therefore, the development of safe, accurate and personalized non-invasive treatment strategies has become one of the key directions of epilepsy research. In recent years, photobiomodulation (PBM) has gained significant attention as a promising non-invasive therapeutic approach. PBM uses light of specific wavelengths to penetrate tissues and interact with photosensitive molecules within cells, thereby modulating cellular metabolic processes. Research has shown that PBM can enhance mitochondrial function, promote ATP production, improve meningeal lymphatic drainage, reduce neuroinflammation, and stimulate the growth of neurons and synapses. These biological effects suggest that PBM not only holds the potential to reduce the frequency of seizures but also to improve the metabolic state and network function of neurons, providing a novel therapeutic avenue for epilepsy treatment. Compared to traditional treatment methods, PBM is non-invasive and avoids the risks associated with surgical interventions. Its low risk of significant side effects makes it particularly suitable for patients with drug-resistant epilepsy, offering new therapeutic options for those who have not responded to conventional treatments. Furthermore, PBM’s multi-target mechanism enables it to address a variety of complex etiologies of epilepsy, demonstrating its potential in precision medicine. In contrast to therapies targeting a single pathological mechanism, PBM’s multifaceted approach makes it highly adaptable to different types of epilepsy, positioning it as a promising supplementary or alternative treatment. Although animal studies and preliminary clinical trials have shown positive outcomes with PBM, its clinical application remains in the exploratory phase. Future research should aim to elucidate the precise mechanisms of PBM, optimize light parameters, such as wavelength, dose, and frequency, and investigate potential synergistic effects with other therapeutic modalities. These efforts will be crucial for enhancing the therapeutic efficacy of PBM and ensuring its safety and consistency in clinical settings. This review summarizes the types of epilepsy, diagnostic biomarkers, the advantages of PBM, and its mechanisms and potential applications in epilepsy treatment. The unique value of PBM lies not only in its multi-target therapeutic effects but also in its adaptability to the diverse etiologies of epilepsy. The combination of PBM with traditional treatments, such as pharmacotherapy and neuroregulatory techniques, holds promise for developing a more comprehensive and multidimensional treatment strategy, ultimately alleviating the treatment burden on patients. PBM has also shown beneficial effects on neural network plasticity in various neurodegenerative diseases. The dynamic remodeling of neural networks plays a critical role in the pathogenesis and treatment of epilepsy, and PBM’s multi-target mechanism may promote brain function recovery by facilitating neural network remodeling. In this context, optimizing optical parameters remains a key area of research. By adjusting parameters such as wavelength, dose, and frequency, researchers aim to further enhance the therapeutic effects of PBM while maintaining its safety and stability. Looking forward, interdisciplinary collaboration, particularly in the fields of neuroscience, optical engineering, and clinical medicine, will drive the development of PBM technology and facilitate its transition from laboratory research to clinical application. With the advancement of portable devices, PBM is expected to provide safer and more effective treatments for epilepsy patients and make a significant contribution to personalized medicine, positioning it as a critical component of precision therapeutic strategies.
10.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Result Analysis
Print
Save
E-mail